RANKING · 2020 CENSUS · 58 SHOWN OF 58

Most population gained, California counties · 2020

California counties that added the most residents from the 2010 census to 2020, by raw count of people rather than percentage. This list covers the 58 counties in California that qualify, ranked against each other statewide.

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SAME RANKING BYCities States Metros

YEAR2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION CHANGEVS 2000

01Riverside County, CACA2,544,916+228,544−39%

02San Diego County, CACA3,282,248+203,321−36%

03Los Angeles County, CACA9,694,934+195,404−70%

04Orange County, CACA3,149,507+176,757−59%

05Alameda County, CACA1,636,630+172,082+5%

06Sacramento County, CACA1,618,460+166,267−9%

07Santa Clara County, CACA1,914,391+154,617−16%

08San Bernardino County, CACA2,224,091+146,444−50%

09Contra Costa County, CACA1,170,070+116,902−19%

10San Joaquin County, CACA823,815+93,927+13%

11Fresno County, CACA1,035,456+78,204−41%

12Kern County, CACA927,068+69,604−41%

13San Francisco County, CACA826,079+68,730+30%

14Placer County, CACA442,081+56,307−26%

15San Mateo County, CACA743,568+45,991−20%

16Solano County, CACA455,376+40,147−26%

17Stanislaus County, CACA557,719+38,425−50%

18Tulare County, CACA485,146+30,938−45%

19Merced County, CACA297,260+25,409−21%

20Santa Barbara County, CACA442,065+24,334−18%

21Monterey County, CACA433,729+23,978−48%

22Ventura County, CACA830,851+20,525−76%

23Yolo County, CACA224,410+15,554−44%

24San Luis Obispo County, CACA282,367+12,787−57%

25El Dorado County, CACA192,323+10,127−67%

26Marin County, CACA253,694+9,912−42%

27Yuba County, CACA88,691+9,420+373%

28San Benito County, CACA70,082+8,940−46%

29Santa Cruz County, CACA258,852+8,479−67%

30Madera County, CACA167,927+5,390−85%

31Imperial County, CACA181,411+5,174−84%

32Sonoma County, CACA486,444+4,985−93%

33Shasta County, CACA181,648+4,932−70%

34Sutter County, CACA98,787+4,896−66%

35Mendocino County, CACA88,122+3,760−36%

36Lake County, CACA67,772+3,498−54%

37Nevada County, CACA101,911+3,477−74%

38Amador County, CACA41,876+2,383−53%

39Tehama County, CACA64,665+2,366−63%

40Trinity County, CACA15,720+2,326−5773%

41Humboldt County, CACA131,647+1,840−75%

42Napa County, CACA132,949+1,535−89%

43Glenn County, CACA28,141+795−52%

44Inyo County, CACA18,158+470−240%

45Colusa County, CACA21,836+420−83%

46Tuolumne County, CACA53,160+255−96%

47Alpine County, CACA1,043+29−69%

48Sierra County, CACA3,098-4−102%

49Plumas County, CACA18,583-217−120%

50Calaveras County, CACA46,605-286−103%

51Kings County, CACA154,327-496−102%

52Siskiyou County, CACA42,013-824−207%

53Del Norte County, CACA26,410-867−121%

54Modoc County, CACA8,426-986+331%

55Mono County, CACA12,505-1,007−135%

56Mariposa County, CACA16,918-1,120−140%

57Lassen County, CACA28,117-2,165−135%

58Butte County, CACA209,211-8,368−140%

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UPDATED 2026-07-15 · DATA: US CENSUS BUREAU DECENNIAL CENSUS